title: The use of flow cytometry for the detection of subvisible particles in therapeutic protein formulations.
abstract: The amount, identity, and size distribution of particles in parenteral therapeutic protein formulations are of immense interest due to potential safety and efficacy-related implications. In this communication, we describe the use of a flow cytometer equipped with forward- and side-scattering as well as fluorescence detectors, to determine the number of subvisible particles in monoclonal antibody formulations. The method appears to detect particles of size 1 μ and larger, requiring relatively small sample volumes to estimate subvisible particle counts. Additionally, it facilitates differentiation of proteinaceous particles after staining with a fluorescent hydrophobic dye. The method is expected to be particularly well suited for pharmaceutical development, because it provides increased throughput due to the use of a 96-well autosampler.
authors.affiliation: Merck Research Laboratories, Bioprocess Analytical and Formulation Sciences, West Point, Pennsylvania 19486, USA. henryk.mach@merck.com
authors.forename: Henryk
authors.initials: H
authors.lastname: Mach
authors.forename: Akhilesh
authors.initials: A
authors.lastname: Bhambhani
authors.forename: Brian K
authors.initials: BK
authors.lastname: Meyer
authors.forename: Steven
authors.initials: S
authors.lastname: Burek
authors.forename: Harrison
authors.initials: H
authors.lastname: Davis
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Blue
authors.forename: Robert K
authors.initials: RK
authors.lastname: Evans
mesh_terms: D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D010316:Particle Size; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D004364:Pharmaceutical Preparations; D011506:Proteins; D011994:Recombinant Proteins